Loose front rotor

I've been hearing some occasional noise from the front right and this weekend took some time to figure out what it is. After taking off the front right tire, at first I noticed that the 4 wheel posts were loose relative to the rotor, but after trying to move the rotor, the rotor itself wiggles back and forth a half inch or so (which I'm assuming is BAD). I took the dust cap off the wheel hub nut (hope I'm calling the right thing) and the nut itself seems very tight. What else might account for a loose rotor?

The only work I've done is to change the front brake pads several months ago (although the left rotor assembly seems very tightly attached (no movement)). Would any work of moving the brake calipers around have affected the rotor looseness?

Other than the wheel hub nut, I'm not sure what to look at. Any suggestions?

Thanks.

Reply to
Mark
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I would take a close look at the caliper assembly and the brackets that it attaches to. The rotor is held on by the caliper and the wheels, it can be removed entirely without even messing with the hub.

With the wheel off, the caliper should keep the rotor in place with little to no movement unless you were to put a lot of force on it.

Have you tried swinging the caliper off of the rotor, tie it in place out of the way, and then tighten down two open-end lugnuts onto the rotor to see if it holds firmly in place or not?

Good luck!

Pat

Reply to
pws

Replying to my own post, scary.... I did not word that last one very well. The rotors are held in place by the lugnuts, which secure both the wheels and the rotors. With the wheel off and the caliper out of the way, the rotor will pop right off of the lugnut studs assuming that it isn't frozen in place, which your's obviously is not.

The two lug nuts will hold the rotor down as if the wheel were in place and let you see things more clearly. The lugnuts need to be open-end because the closed acorn-style lugnuts don't go down far enough.

Basically, if the wheel is tightened, there should be no play in your rotor. That is why I would look at the caliper first, it may be missing a return spring for the brake pads or have some other problem.

HTH,

Pat

Reply to
pws

I finally got a chance to look at it last night (thank goodness for public transportation). I took the wheel off and swung the calipers out of the way. The rotor assembly with the pads attached is very loose. I'll have to get behind the whole hub assembly with a better light than I had yesterday. With the wheel and calipers off should the rotor be movable (I don't mean rotationally, but side to side)? Maybe I'm chasing the wrong thing, but the left rotor with the wheel off is very firmly fixed in place, unlike the right side.

Reply to
Mark

Hmmmmm, the rotor shouldn't be very loose with the caliper in place, but is is moveable just because the brake piston/pads are, plus the front calipers can not be locked like the rears with the e-brake, so the pads should be a *very* small distance away from the rotors anyway. Your left side sounds more normal unless the rotor is stuck in place.

The caliper/brake pads are all that is holding the rotor in place once the wheel is off, but the caliper goes down pretty far on the rotor and the brakes pads should hold it pretty much in place unless you start pulling on it. There still won't be room for the rotor to come free until the caliper has been disconnected and moved at the rotor end.

Once the caliper is out of the way, there is nothing to keep the rotors on. They should be very loose at this point and just pop right off of the lugnuts as easily as the wheels. If not, a rubber hammer will usually do it, but your right one is obviously not stuck. It should be very obvious how to remove the rotors once you have the caliper loose and out of the way, literally like taking off a small wheel.

The question remains as to why your car is making noise during braking.

Since the rotor is loose within the brake pads on the right side and not the left, that is where I would suspect the problem is, the caliper and/or brake pad assembly. Have you tried pushing the piston in to see if it goes in and out normally and have you checked to make sure that all of the brake pad parts are properly in place within the caliper? How do the pads looks compared to the left side?

Pat

Reply to
pws

Pat,

I think that Mark:

  1. Doesn't understand that the rotor is actually held in place by compression of the lug nuts against the wheel against the rotor. You explained this very well.

  1. Thinks that his left rotor, which is probably frozen in place by rust, is "firmly fixed", which it isn't and the right rotor, because it is "movable", has something wrong with it, which it doesn't.

In fact: the right rotor is behaving normally and he needs to whack the left rotor with a rubber mallet to free it, should it need turning or replacement.

He said that the "4 wheel posts" were loose, relative to the rotor. I hope what he means is that the rotor was loose, relative to the four wheel studs. I guess it's not impossible for the four studs to somehow be loose, but it doesn't seem likely. Even if they were, torquing down the lug nuts would still firm up the entire assembly.

He also said that the noise was "occasional" and, in a later post, that he had replaced the front brake pads several months ago.

I think a good question for Mark is: Can you give us more information about the noise? Is it a grinding noise when you stop...or a thump or click...or does it have nothing to do with braking (this was not clear in the initial post).

My '90 developed a "thunk" noise when I initially pressed the brake pedal. I finally diagnosed this as my failure to replace the backing plates when I changed the pads. The old plates had an impression of the piston face in them and, apparently, the location of this impression would move around. It appeared that the act of backing up and stopping would aggravate the sound as the impression and piston face would re-align with a thunk.

Please tell us more about your particular noise, Mark.

Ken

pws wrote:

Reply to
KWS

Thanks Ken, I think you covered anything I missed.

Funny, I did the exact same thing on my first pad replacement. The brakes felt fine, but made a clunking sound. These were some aftermarket pads that had no hardware, and I had already tossed the backing plates.

I know it is hard to believe, but Mazda does not sell the brake pad hardware alone. So, a new set of OEM pads later, with all new hardware, and the noise was gone. I felt better having a new set of return springs anyway. The only reason that I used the aftermarket pads is that they were free. I got a full 2 or 3 hundred miles out of them.

Pat

Reply to
pws

Ok, having looked at the wheels and rotors enough now I see that the rotor being loose on the right is perfectly ok. And having taking it apart and put it all back together a few times, I'm happy that all is as it should be.

My first attempt at doing so and then driving resulted in a jangling noise every time I hit a bump on the right front wheel. Taking the wheel off (again) I discovered I hadn't put the wheel nut dust cover on properly and it had popped off. Now I'm not hearing any noises to be worried about (well, ok, my lifters ticking are a different story and for another post).

Thanks for help> Pat,

Reply to
Mark

No problem at all. We actually talk about miatas once in a while in between discussions on boats and politics.

Glad you got it worked out. The lifter noise is not a big deal. When was the last time you changed the oil and are you using a OEM Mazda oil filter?

Pat

Reply to
pws

and tortoises...

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